NAME
Data::Inherited - Hierarchy-wide accumulation of list and hash results
VERSION
version 1.100860
SYNOPSIS
package Foo;
use base 'Data::Inherited';
use constant PROPERTIES => (qw/name address/);
package Bar;
use base 'Foo';
use constant PROPERTIES => (qw/age/);
package main;
my $bar = Bar->new;
print "$_\n" for $bar->every_list('PROPERTIES');
# prints:
#
# name
# address
# age
DESCRIPTION
This is a mixin class. By inheriting from it you get two methods that
are able to accumulate hierarchy-wide list and hash results.
METHODS
every_list(String $method_name, Bool ?$override_cache = 0)
Takes as arguments a method name (mandatory) and a boolean indicating
whether to override the cache (optional, off by default)
Causes every method in the object's hierarchy with the given name to be
invoked. The resulting list is the combined set of results from all the
methods, pushed together in top-to-bottom order (hierarchy-wise).
"every_list()" returns a list in list context and an array reference in
scalar context.
The result is cached (per calling package) and the next time the method
is called from the same package with the same method argument, the
cached result is returned. This is to speed up method calls, because
internally this module uses NEXT, which is quite slow. It is expected
that "every_list()" is used for methods returning static lists (object
defaults, static class definitions and such). If you want to override
the caching mechanism, you can provide the optional second argument. The
result is cached in any case.
See the synopsis for an example.
every_hash(String $method_name, Bool ?$override_cache = 0)
Takes as arguments a method name (mandatory) and a boolean indicating
whether to override the cache (optional, off by default)
Causes every method in the object's hierarchy with the given name to be
invoked. The resulting hash is the combined set of results from all the
methods, overlaid in top-to-bottom order (hierarchy-wise).
"every_hash()" returns a hash in list context and a hash reference in
scalar context.
The cache and the optional cache override argument work like with
"every_list()".
Example:
package Person;
use base 'Data::Inherited';
sub new {
my $class = shift;
my $self = bless {}, $class;
my %args = @_;
%args = ($self->every_hash('DEFAULTS'), %args);
$self->$_($args{$_}) for keys %args;
$self;
};
sub DEFAULTS {
first_name => 'John',
last_name => 'Smith',
};
package Employee;
use base 'Person';
sub DEFAULTS {
salary => 10_000,
}
package LocatedEmployee;
use base 'Employee';
# Note: no default for address, but different salary
sub DEFAULTS {
salary => 20_000,
first_name => 'Johan',
}
package main;
my $p = LocatedEmployee->new;
# salary: 20000
# first_name: Johan
# last_name: Smith
flush_every_cache_by_key(String $key)
Deletes the cache entry for the given key.
INSTALLATION
See perlmodinstall for information and options on installing Perl
modules.
BUGS AND LIMITATIONS
No bugs have been reported.
Please report any bugs or feature requests through the web interface at
.
AVAILABILITY
The latest version of this module is available from the Comprehensive
Perl Archive Network (CPAN). Visit to find a
CPAN site near you, or see
.
The development version lives at
. Instead of sending
patches, please fork this project using the standard git and github
infrastructure.
AUTHOR
Marcel Gruenauer
COPYRIGHT AND LICENSE
This software is copyright (c) 2004 by Marcel Gruenauer.
This is free software; you can redistribute it and/or modify it under
the same terms as the Perl 5 programming language system itself.